Product Code: ICA11_M1003

Picosecond Laser Machining of Fiber Based Sensing Devices
Authors:
Frank Albri, Heriot-Watt University and Scottish Universities Physics Alliance [SUPA]; Edinburgh Scotland
Jun LI, Heriot-Watt University and Scottish Universities Physics Alliance [SUPA]; Edinburgh Scotland
Robert R. J. Maier, Heriot-Watt University and Scottish Universities Physics Alliance [SUPA]; Edinburgh Scotland
William N. MacPherson, Heriot-Watt University and Scottish Universities Physics Alliance [SUPA]; Edinburgh Scotland
Duncan P. Hand, Heriot-Watt University and Scottish Universities Physics Alliance [SUPA]; Edinburgh Scotland
Presented at ICALEO 2011

The applications of fused silica optical fibre based sensors are widespread, from strain or temperature measurement to fibre-tip sensors, and provide potential sensor solutions for environments where electronic sensors fail or are otherwise unsuitable. Fused silica is a very strong but challenging material to machine. Precision micro-machining of fused silica is possible using expensive femto-second lasers, but the material removal rates are very low. Alternatively, focused ion beam machining has been used to great effect, and is capable of high quality surface finish and small machined feature size but again is a very slow process using a very expensive machine and cannot achieve high aspect ratio features such as cuts, slots or deep holes. We report on our work using pico-second laser pulses to ablate features such as cantilever components and sensor cavities machined from fused silica fibre. The technique shows promising and versatile results enabling flexible production of different devices such as extrinsic Fabry Perot cavities and cantilevers on the top or side of a fibre for mechanical sensing applications. Optical interrogation of such elements requires a suitable optical finish and we will present results on surface quality and cut rate.